mdreloc.c revision 1.19
1 /* $NetBSD: mdreloc.c,v 1.19 2003/07/24 10:12:29 skrll Exp $ */ 2 3 #include <sys/types.h> 4 #include <sys/stat.h> 5 6 #include "debug.h" 7 #include "rtld.h" 8 9 void _rtld_bind_start(void); 10 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr); 11 caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); 12 13 void 14 _rtld_setup_pltgot(const Obj_Entry *obj) 15 { 16 obj->pltgot[1] = (Elf_Addr) obj; 17 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 18 } 19 20 void 21 _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase) 22 { 23 const Elf_Rela *rela = 0, *relalim; 24 Elf_Addr relasz = 0; 25 Elf_Addr *where; 26 27 for (; dynp->d_tag != DT_NULL; dynp++) { 28 switch (dynp->d_tag) { 29 case DT_RELA: 30 rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr); 31 break; 32 case DT_RELASZ: 33 relasz = dynp->d_un.d_val; 34 break; 35 } 36 } 37 relalim = (const Elf_Rela *)((caddr_t)rela + relasz); 38 for (; rela < relalim; rela++) { 39 where = (Elf_Addr *)(relocbase + rela->r_offset); 40 *where = (Elf_Addr)(relocbase + rela->r_addend); 41 } 42 } 43 44 int 45 _rtld_relocate_nonplt_objects(const Obj_Entry *obj) 46 { 47 const Elf_Rela *rela; 48 49 for (rela = obj->rela; rela < obj->relalim; rela++) { 50 Elf_Addr *where; 51 const Elf_Sym *def; 52 const Obj_Entry *defobj; 53 Elf_Addr tmp; 54 unsigned long symnum; 55 56 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 57 symnum = ELF_R_SYM(rela->r_info); 58 59 switch (ELF_R_TYPE(rela->r_info)) { 60 case R_TYPE(NONE): 61 break; 62 63 #if 1 /* XXX should not occur */ 64 case R_TYPE(GOT32): 65 def = _rtld_find_symdef(symnum, obj, &defobj, false); 66 if (def == NULL) 67 return -1; 68 69 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 70 rela->r_addend); 71 if (*where != tmp) 72 *where = tmp; 73 rdbg(("GOT32 %s in %s --> %p in %s", 74 obj->strtab + obj->symtab[symnum].st_name, 75 obj->path, (void *)*where, defobj->path)); 76 break; 77 78 case R_TYPE(REL32): 79 def = _rtld_find_symdef(symnum, obj, &defobj, false); 80 if (def == NULL) 81 return -1; 82 83 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 84 rela->r_addend) - (Elf_Addr)where; 85 if (*where != tmp) 86 *where = tmp; 87 rdbg(("PC32 %s in %s --> %p in %s", 88 obj->strtab + obj->symtab[symnum].st_name, 89 obj->path, (void *)*where, defobj->path)); 90 break; 91 #endif 92 93 case R_TYPE(DIR32): 94 def = _rtld_find_symdef(symnum, obj, &defobj, false); 95 if (def == NULL) 96 return -1; 97 98 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 99 rela->r_addend); 100 if (*where != tmp) 101 *where = tmp; 102 rdbg(("32 %s in %s --> %p in %s", 103 obj->strtab + obj->symtab[symnum].st_name, 104 obj->path, (void *)*where, defobj->path)); 105 break; 106 107 case R_TYPE(GLOB_DAT): 108 def = _rtld_find_symdef(symnum, obj, &defobj, false); 109 if (def == NULL) 110 return -1; 111 112 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) + 113 rela->r_addend; 114 if (*where != tmp) 115 *where = tmp; 116 rdbg(("GLOB_DAT %s in %s --> %p in %s", 117 obj->strtab + obj->symtab[symnum].st_name, 118 obj->path, (void *)*where, defobj->path)); 119 break; 120 121 case R_TYPE(RELATIVE): 122 if (rela->r_addend) 123 *where = (Elf_Addr)obj->relocbase + rela->r_addend; 124 else 125 *where += (Elf_Addr)obj->relocbase; 126 rdbg(("RELATIVE in %s --> %p", obj->path, 127 (void *)*where)); 128 break; 129 130 case R_TYPE(COPY): 131 /* 132 * These are deferred until all other relocations have 133 * been done. All we do here is make sure that the 134 * COPY relocation is not in a shared library. They 135 * are allowed only in executable files. 136 */ 137 if (obj->isdynamic) { 138 _rtld_error( 139 "%s: Unexpected R_COPY relocation in shared library", 140 obj->path); 141 return -1; 142 } 143 rdbg(("COPY (avoid in main)")); 144 break; 145 146 default: 147 rdbg(("sym = %lu, type = %lu, offset = %p, " 148 "addend = %p, contents = %p, symbol = %s", 149 symnum, (u_long)ELF_R_TYPE(rela->r_info), 150 (void *)rela->r_offset, (void *)rela->r_addend, 151 (void *)*where, 152 obj->strtab + obj->symtab[symnum].st_name)); 153 _rtld_error("%s: Unsupported relocation type %ld " 154 "in non-PLT relocations\n", 155 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 156 return -1; 157 } 158 } 159 return 0; 160 } 161 162 int 163 _rtld_relocate_plt_lazy(const Obj_Entry *obj) 164 { 165 const Elf_Rela *rela; 166 167 if (!obj->relocbase) 168 return 0; 169 170 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) { 171 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 172 173 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 174 175 /* Just relocate the GOT slots pointing into the PLT */ 176 *where += (Elf_Addr)obj->relocbase; 177 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 178 } 179 180 return 0; 181 } 182 183 caddr_t 184 _rtld_bind(const Obj_Entry *obj, Elf_Word reloff) 185 { 186 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff); 187 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 188 Elf_Addr new_value; 189 const Elf_Sym *def; 190 const Obj_Entry *defobj; 191 192 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 193 194 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 195 if (def == NULL) 196 _rtld_die(); 197 198 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 199 rdbg(("bind now/fixup in %s --> old=%p new=%p", 200 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 201 if (*where != new_value) 202 *where = new_value; 203 204 return (caddr_t)new_value; 205 } 206 207
Indexes created Tue Sep 30 11:09:46 GMT 2025